Means for eliminating dust produced by pneumatic drills



Jan. 8, 1952 L. A. JEAN-BAPTISTE DAUTREBAN'DE 2,581,943

MEANS FDR ELIMINATING DUST PRODUCED BY PNEUMATIC DRILLS Filed Nov. 29, 1946 4 2 SHEETS-SHEET l Jan- 8, 1952 L. A. v.lr-:AN-BMW'ISTE DAUTREBANDE 2,581,943

I -MEANS FOR ELIMINTING DUST PRODUCED BY PNEUMATIC DRILLs Fild Nov. 29, 194e 2 SHEETS- SHEET 2 mvENToR Patented' Jan. 8, 1952 UNI TED STAT MEANSFDR ELIDIINATING'DUST PRODUCED 1 BY PNEUMATICDRILLS Lucien Adolphe. Jean-Baptiste vlDautrebamile,

Rhode-Saint-Genese, Belgium, Aerosol Corporation of America, N. Y., a corporation oi Delaware assigner to New York,

vApplication November 29, A194,6,,SerialfNo. 713,058

. InfBelziumxNovemberSI), 1945.

4' Claims. (Cl. 2551-49) My present'invention relates to the elimination of dust produced by pneumatic apparatusvsuch as'piercing tools, pneumatic drills, drillingmachinesand similar devices.

It knownv that all pneumatic apparatus functioning on friable/ material automatically produces acertain amountof dust. The amount producediis"inproportionto the volumelrlow of airatazgiven pressure from the'apparatus.

-The'dust produced tends to remain in the atmosphereand causes many "inconveniences from the point of view of the eiiiciency of the work beingfperformed. The dust is the moreinj'urious-the liner itfbecomes.

In' the-minesA therecovery or'elimination" of ther1 dust usually has been made by Ventilating galleries andi-by certainv imperfect'practices atl the :source of dust formation.

According to the present invention thesein'-V conveniences are'remediedin that dust-is eliminated;byrecuperation,e removal, settling, etc;, at' the sourcesaitself. and bythe functioning; of`vl the- Ipneumaticq-apparatus which'l generates the fdust. The..y pneumatic; drill -I apparatuszfor example,-

mayfbessurroundedby a sheath'or supplementaryl arrangement in :which is ;provided an. aspirating jet connected to the outlet of.,thei:compressed. airi after: expansion'. within the dri1l,. which 1 jet acts to. eilectavv suction withintheisheath .and so' draw.

in.: the dust vas dormed and thusto: eliminate it'.

by aspiration to a degreefdependentonsitsipro@` duction; Itymay; be.v so. removed byfpreferencef as faras possible.: bya system. of.: pipes. connected..

tothissheath.`

The dust Within thefzone-of suction isitreated';

by:y aerosols obtained from an adequate generating solutionfand suitable. for producing precipitation,`

ilxation or neutralisation of the dustproduced 'by the operation ofi the pneumatic. apparatus. In. this connection. the compressed. air..V serving to operatethe. apparatus may be, beforeits introfductiom charged with liquid. or solid aerosols. l.

of'the drill during, the percussion movementand. reIasedinto-the immediate atmosphere around.

theV user.

In order to furtherv illustrate theinvcntion the following4 non-limitative examples and aecompanyingdrawings are setforth.

' Figs. 1 and 2 eachshowlmy inventionas-V applied to apneumatic .drill and utilizinganexternali source: of aerosols. and asheath.

. 2. Y Fig. 3 isa section'on'the line III-HI ofp-Fign' 1'." Fig. 4 illustrates my invention as applied toia pneumatic drill and-utilizing anintegralisource of'aerosol.Y Fig. 5 is a further showingof the apparatus of Fig 4 illustrating the source and controlof the" liquid to be dispersed.

Iny Fig. l, the cylinder` I of the drillcarries ai pistoniv which acts in the'Well known manner4 by percussion on a' drill bit 3. CompressedairE is supplied to the-pneumatic drill'by a flexible-r tube 4. The apparatus'has thenose 5 andthe" escape screen 'I. Thel air'escapes'from the'cylini-fder I and emergesv through openings 8 and-f 9A n'toa spacevIIl.

According-'to thisembodiment 'of the invention' the drill is surrounded over almost' theentire` length of the cylinder by a supplementary sheath.` II. Within the sheath II there isan-aspirating'` jet' I2. attached'to the.V outlet in screenxl forv the compressedair after expansion;

The air is directed by means of the .aspirating f jet'. I2' into a tube, I3 which is` eonnectedto the sheath II. The' .aspirating action or. suctionA which takes place in the space comprised-:bev tween the sheath Hand cylinder .I of the; drill isparticularly felt at I4 at the point wherethe.;

dust is produced. The'dustis drawn into. the sheathII andis carried away by the airrpassed; along the tube I3. Thetube I3,if desired,.can surroundconcentricallyftheztube 4.-for bringingjin the compressed air. l A

Furthermore, the lsheath I I I is notnecessarily;Y

brought as far, as the'drll bit3vbut can stop,-y belowthe .partof the cylinder where are vlocated the escapeapertures.

Compressed. air in the tube II operatesthe ap, paratus of Fig. landis chargedbeforeitsintro, ductioninto-the apparatus, with particles form-` ing a. dispersion, of liquid, viscous material,

' foam, :wetting agent or. pulversedlsolid. .Aerosols through the outlet tube I3.

obtained for example bydispersion of liquid-by meansof. a gas.. are preferred. As a solidma-f terial, aluminium :powder or hydrate .can be cited.

The dust is agglutinated 'during the. passage.A

Furthermore the precipitating coating, sticking, enrobing or neutralising `particles which have not yet beenj-.xed-

on the particles of dust can be utilisedfat the exit of` thetube I3 to participate inthe steriliza--U4 tion of. the generalatmosphere.

v,'Ihis-principle is useful for the recovery and;

iixing of dust not `only at the source butalsoin case` of need for the supplyof aerosolsinto. the.

atmosphere situated at a distance from thepneu-f Vf of the sheath II and the spacing of the sheath opposite the aspirating jet I2 is greater.

Theaspirating tube I3 should be larger than l the inlet tube for the compressed air. A screw controlled valve I4 permits of regulating the intensity of the aspiration according to variation in the functioning of the drill.

' drawing tube I3.

4 goes chemical reaction with the particles or the droplets selected.

In Figs. 1 and 2, like reference numerals refer tolikeparts. f

In the embodiment according to Fig. 2 there is no jet I2 to act as an aspirator and no with- The supplementary sleeve 28 gathers after expansion, all the compressed air charged with'aerosols emerging at 8 and directs According to the invention, as shown in Fig. 2, v

part of the compressed air coming from a suitable source passes through a tube I5 in its trajectory towards the drill and through an aerosol producing device I6 containing at I'I a solutionv or a suspension to be dispersed. This liquid can advantageously be utilised simultaneously as a lubricant.

Within the aerosol producing device there is an atomising jet represented diagrammatically at I8 provided with an air inlet (I5) and a liquid inlet (tube I9).

The cloud formed at the outlet of the jet I8 is advantageously submitted to a stabilisation process for the small particles by 'selection and for this purpose can be directed on an inclined surface and block 23 which is the interior wall of the outlet tube 2I and which gives rise at 22 and 23 to thevformation of a continuous liquidnlm which acts as described in mycopending United States patent application, Serial No. 'lOl-,216, namely, as a selection agent whereby the particles whichV have not reached the requisite degree of stability to traverse the liquid layer are returned to the mother solution.

' YOther selection means and suitably such means Adescribed in said co-pendingA patent application can be used.

A tube 4 connects the outlet tube 2l with the tube #and the aerosols mix with the air brought by the tube 4.

It is preferably arranged that the quantity of liquidcontained in the aerosol producing device is always constant as this avoids the necessityrof recharging the aerosol'producing device and renders the arrangement automatic.

For this purposel a tubev 24 vsituated within the aerosol producing device I1 is used,-the outlet forwhich is below the level of the liquid corresponding-to the minimum quantity of liquid the'presence of which is required or necessary. l

This tube outside the apparatus is connected through a flexible tube 25 having a tap 26 to'fa hermetically sealed vessel 21 so that when the level of the liquid in the aerosol producing device it towards the outside along the axis of the pneumatic drill so as to permit the fixation of all the dust at the point where it is formed by the drill bit 3.

The same principle can be adapted for the hollowing out of openings or other galleries or for all other types of public work (demolition. concrete breaking, crushing, etc.)

Similarly in apparatus inA which water is used to iix the dust a current of air can be replaced by a jet of aerosols issuing from suitable solutionsy notably froths. This method of procedure avoids a dangerous increase in the moisture content of the air, fixes the dust of all shapes and only rel Vquires a minimum quantity of liquid.

Fig. 4 relates to a variation of the embodiment. based on a cooperation with the exit of the airf-v of a tube supplied with water or other liquid under pressure whereby a cloud of aerosols is formed which is directed towards the source of the dust. l y

The pneumatic drill may be provided at its periphery with a tube 29 tted over the escape aperture for the air and directing the air by means of a small cup 29 away from the hand. grip.P. Through this tube there passes part=or preferably the whole of the air coming from-the drill.

Opposite the outlet for thel air there Ais provided l a water jet or jet ofanother liquid preferablyi` under pressure.A The jet is providedwith af tapered orice at the extremity of aishort rigidi tube 30 to which is attached a flexible tube 3l for bringing in the water.- AThe rigid tube 30 isvv carried by the body of the drill for` example with? the aid of a ringv32, ,z Y. s` p The tube 3I can. also .be connected o a source". suppliedv withany other liquid, viscousor solid 1 material '(aluminium powder or hydrate), l(also:

foams, wetting agents, etc.). l Y

The distance betweenA the outlet tube for-'the air and that for the water or other-materialcani be regulated for example with the aid of a screw? 33 acting to move the tube 30.

islow1there is produced an automatic ilow of A liquid from the reservoir 21 towards the layer II. If desired, the air thus charged with aerosols on emerging from the instrument expands into the atmosphere in the immediate vicinity of the" user and can serve for the precipitation and fixingof the dust raised by the action of the pneumatic drill. This airin the majority of cases emerges bythe orifices 8 and 9A which are provided of necessity within the body of the drill and the percussion movement. It is therefore Vpossible to arrange that all the air emerging from a pneu-y matic drill or any other type of pneumatic apparatus is charged with effective concentrations of neutral liquids,'viscous liquids, precipitates or neutralising agents.-V The neutralisation is vespe- .f Under suitably regulated conditions the air and'vv water.v upon meeting form a cloud of 'aerosols'` which maybe directed` along the axis of lthe; cavity formed bythe drill 3'.V i

'Y The pressure ofwater supplied bythe tube 3'I i' should be regulated by appropriate means-soa's" to prevent the penetration of Water into the bodyY ofthe drill and to obtain an optimum pulverisav tion at theoutlet of the air from the drill. Thisv ,optimum depends equally on the regulation'-off-L the relative positions of the tubes29 and 30.

The liquid under pressure as in Fig. 5 advanff tageuslycan be provided bya vessel 3 4 at'thejfA base of which is connected the flexible tube ,3,Ij.

' ,Into this vessel is introduced lasa pressure agent,"

compressed air from a source which'is indes. pendent or connected by 'a tube 31 with'the1 common conduit 36 supplying the compressedair for the operation ofthe drill; l

A tap can be providedat 35 `forregulatingjthefr cially necessary for removing dust whichunder- Vv'75 pressure ofthe air acting 'oirthe liquid inthe iiask 34. There is thus provided a means for regulating the pressure of the liquid.

The liquid can comprise viscous, sticking, froths, neutralising solutions, etc., according to the nature of the dust desired to be controlled.

What I claim is:

1. A device for eliminating air-borne dust generated by the operation of a pneumatic drill comprising, in combination, means for the production of an aerosol, means for mixing aerosol with compressed air, means for charging the drill mechanism with aerosol-compressed air mixture to operate the same, a sheath surrounding said drill mechanism, defining a space therebetween and having an annular opening at the lower end thereof, and exhaust means connecting said drill mechanism with the space within said sheath for introducing aerosol-air mixture therewithin and arranged to direct a iiow of aerosol therewithin for bringing the aerosol into contact with the dust.

2. A device in accordance with claim 1 in which the sheath is provided with a second opening at its other end. and the exhaust means is arranged to direct a ow of aerosol-air mixture towards and out said opening to suck air-borne dust into the space between the sheath and the drill mechanism through the rst-mentioned annular opening of the sheath.

3. A device in accordance with claim 1 in which the exhaust means connects said drill mechanism with the space within said sheath for introducing aerosol-compressed air mixture therewithin is arranged to direct a ilow of aerosol out said annular opening.

4. A device for eliminating air-borne dust generated by the operation of a pneumatic drill, comprising, in combination, means for the production of an aerosol, means for mixing aerosols with compressed air, means for charging the drill mechanism with aerosol-compressed air mixture to operate the same, a sheath surrounding said drill mechanism, defining a space therebetween and having an annular opening at the lower end thereof and a second annular opening at the upper end thereof, exhaust means connecting said drill mechanism with the space within said sheath for introducing aerosol-compressed air mixture therewithin and arranged to direct 9, flow of aerosol-compressed air mixture towards and out said second opening to suck airborne dust into the space between the sheath and the drill mechanism through the rst-mentioned annular opening of the sheath, and an inlet tube for compressed air directed into said sheath adjacent the second opening to assist in driving aerosol-compressed air-dust mixture out the second opening, the second opening in the sheath being larger in diameter than the inlet tube for compressed air.

LUCIEN ADOLPHE JEAN-BAPTISTE DAUTREBANDE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 981,409 Goodspeed Jan. 10, 1911 1,084,152 Kessel Jan.,13, 1914 1,223,027 Brackett Apr. 17, 1917 1,334,430 Ayotte Mar. 23, 1920 2,009,066 Mitchell July 23, 1935 OTHER REFERENCES Publication by American Cyanamid 8: Chemical Corp., "Aerosol Wetting Agents, 1941. 

